RESUMO
A 1 cm diameter mass was detected in the caudal superotemporal area of the left eye of a 6-year-old neutered male ferret (Mustela putorius furo). The mass and the left eye were removed surgically. Microscopical examination revealed a tumour of the adnexal gland of the eye that had invaded the surrounding ocular muscle. The tumour was composed of basal-type epithelial cells arranged in a solid, or occasionally tubular, pattern. Immunohistochemically, the tumour cells expressed cytokeratin and p63, but not smooth muscle actin. Based on these findings, the tumour was diagnosed as a basal cell adenocarcinoma of the lachrymal gland. In addition to the tumour, the retina of the left eye was detached and folded at the centre of the globe. This is the first report of a non-human case of basal cell adenocarcinoma of the lachrymal gland.
Assuntos
Adenocarcinoma/veterinária , Neoplasias Oculares/veterinária , Furões , Animais , MasculinoRESUMO
We investigated functional organization of the vagus nerve (N. X)- and glossopharyngeal nerve (N. IX)-related nuclei in the embryonic rat brainstem and compared their development and spatial distribution patterns, using multiple-site optical recording with a fast voltage-sensitive dye, NK2761. Intact brainstem preparations with N. X and N. IX attached were dissected from E13-E16 rat embryos, and electrical responses evoked by N. X/N. IX stimulation were optically recorded from many loci of the stained preparations. We analyzed optical waveforms and separated fast and slow optical signals corresponding to the antidromic/orthodromic action potentials and the excitatory postsynaptic potentials (EPSPs), respectively. We constructed contour line maps of signal amplitudes and identified motor and sensory nuclei of N. X and N. IX. In the N. X-related motor nucleus (the dorsal motor nucleus of the vagus nerve: DMNV), the fast signals were distributed in multiple-peak patterns, suggesting that the neurons and/or their activity are not distributed uniformly within the motor nuclei at early developmental stages. In the sensory nucleus (the nucleus of the tractus solitarius: NTS), the EPSPs were first detected from E15 in normal physiological solution for both N. X and N. IX. The N. IX-related NTS partially overlapped with the N. X-related NTS, but the peak locations were different between these two nerves. The results obtained in this study suggest that functional organization of the N. X- and N. IX-related nuclei changes dynamically with development in the embryonic rat brainstem.
Assuntos
Mapeamento Encefálico/métodos , Nervo Glossofaríngeo/embriologia , Nervo Vago/embriologia , Animais , Corantes , Embrião de Mamíferos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Nervo Glossofaríngeo/fisiologia , Óptica e Fotônica/métodos , Ratos , Ratos Wistar , Núcleo Solitário/embriologia , Nervo Vago/fisiologiaRESUMO
The aim of this study was to investigate the contribution of various tobacco components to the generation of smoke constituents using a tobacco pyrolysis model. We analyzed the amounts of primary tobacco components (sugars, protein, polyphenols, alkaloids, organic acids, inorganics etc.) in flue-cured and burley tobacco leaves. Each of the components was added to the tobacco leaves at the 0.5-fold and 1.0-fold amount naturally present in the leaves. The treated tobacco samples were pyrolyzed at 800 degrees C in a nitrogen atmosphere with an infrared image furnace, and the selected smoke constituents (benzo[a]pyrene, hydrogen cyanide, carbonyl compounds, aromatic amines, volatile organic compounds and phenolics) were quantitatively analyzed by several methods, including high performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC-MS). The contribution of each tobacco component to the generation of selected smoke constituents was estimated from a regression line determined by the three yields (no addition, 0.5-fold addition, and 1.0-fold addition). The results of this study can provide useful and comprehensive information on the relationship between tobacco components and selected smoke constituents during pyrolysis.
Assuntos
Modelos Teóricos , Nicotiana/química , Fumaça , Cromatografia Gasosa-Espectrometria de Massas , Incineração , Compostos Orgânicos/análise , Folhas de Planta/químicaRESUMO
Developing seeds of the kidney bean (Phaseolus vulgaris L.) contain several isoforms of starch branching enzymes. Two of them, KBE1 and KBE2, which are the major forms in the premature seeds, were purified as a single band of protein on SDS-PAGE and native PAGE by chromatographies on DEAE-Sepharose, Bio-Gel P-200, and amylose-binding Sepharose 6B. The enzymes had similar pH optimum (7.0), pH stability (7.0-9.5), temperature optimum (25-30 degrees C), and temperature stability (up to 40 degrees C). Additionally, both were inhibited by various divalent metal ions and activated by citrate. Finally, though their N-terminal amino acid sequences were identical, their molecular masses and affinities for amylose differed; 80 kDa and 1.27 mM for KBE1 and 77 kDa and 0.74 mM for KBE2.
Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/isolamento & purificação , Fabaceae/enzimologia , Sementes/enzimologia , Enzima Ramificadora de 1,4-alfa-Glucana/química , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Sequência de Aminoácidos , Cálcio/química , Cromatografia em Gel , Ácido Cítrico/química , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Fabaceae/embriologia , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , TemperaturaRESUMO
AM-toxins are host-specific phytotoxins of the Alternaria alternata apple pathotype, which induce necrosis on apple leaves. In this study, we developed a new assay to measure the necrotic activity of AM-toxin analogs using cultured leaves from meristem cells. This method was not only more sensitive to AM-toxin I, but also more reliable than the previous one that used tree leaves due to the homogeneous nature of cultured leaves and to the method of application of toxins. Using this assay method we investigated a structure-activity relationship of AM-toxin analogs synthesized in this study. Most residues and the macrocyclic ring structure were strictly recognized by AM-toxin putative receptor, whereas the L-Ala binding subsite of the receptor allowed for side chain structures with various stereoelectronic properties. These findings are important for designing ligands for further experimental probing of the nature of the receptor.
Assuntos
Alternaria/química , Frutas/efeitos dos fármacos , Meristema/efeitos dos fármacos , Micotoxinas/química , Peptídeos Cíclicos/química , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Micotoxinas/farmacologia , Peptídeos Cíclicos/farmacologia , Doenças das Plantas/microbiologia , Especificidade da Espécie , Relação Estrutura-AtividadeRESUMO
The effect on genetically obese mice of a milk whey protein isolate (WPI) and soy protein isolate (SPI) and their hydrolysates (WPI-H, SPI-H) on the rate of body fat disappearance was investigated. Male yellow KK mice were made obese by feeding with a high-fat diet containing 30% fat from 6 to 10 weeks of age. They were then fed with an energy-restricted low fat (5.0%) and high protein (35% WPI, WPI-H, SPI or SPI-H) diet for 2 weeks at the 60% level of energy intake by mice on laboratory feed. During the weight reduction period, the body weight of the WPI, WPI-H, SPI and SPI-H groups changed by -9.1, -9.1, -10.0 and -11.1 g/14 days, respectively, the reduction being significantly lower in the SPI-H group than in the WPI and WPI-H groups. The plasma total cholesterol level was significantly lower with the SPI diet, and the plasma glucose level was lower with the SPI and SPI-H diets than with the WPI and WPI-H diets. Although the body protein content was comparable in all the groups, the body fat content was significantly lower with the SPI diet than with the WPI diet, and was also significantly lower with the SPI-H diet than with the WPI and WPI-H diets. The weight of the perirenal fat pads was significantly lower with the SPI-H diet than with the WPI and WPI-H diets. These results indicate that SPI and SPI-H are suitable protein sources in an energy-restricted diet for treating obesity.
Assuntos
Peso Corporal/efeitos dos fármacos , Proteínas do Leite/farmacologia , Proteínas de Soja/farmacologia , Tecido Adiposo Marrom/efeitos dos fármacos , Aminoácidos/análise , Animais , Glicemia/análise , Colesterol/sangue , Dieta Redutora , Hidrólise , Fígado/efeitos dos fármacos , Fígado/crescimento & desenvolvimento , Masculino , Camundongos , Camundongos Obesos , Proteínas do Leite/química , Tamanho do Órgão/efeitos dos fármacos , Proteínas de Soja/química , Triglicerídeos/sangue , Aumento de Peso/efeitos dos fármacosRESUMO
The cyclic depsipeptides, AM-toxins I and II and AM-toxin I analogs, were efficiently and rapidly prepared by the Fmoc-based solid-phase method for the synthesis of linear depsipeptides, with N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]pyridin-1-ylmethylene]-N-methylmethanaminium hexafluorophosphate N-oxide (HATU) being used for their subsequent cyclization.
RESUMO
We report a 19-year-old man who developed a cerebral infarction in the territory of the anterior choroidal artery and showed a hypercoagulable state and nephrotic syndrome after diarrhea and appetite loss. He had suffered from nephrotic syndrome from the age of three and had been treated for five years. MR-angiography showed an occlusion originating in the right internal carotid artery. The right anterior and middle cerebral arteries were imaged from the left internal carotid artery via the anterior communication artery. He showed symptoms of left hemiparesis, agnosia, loss of activity, anasarca and left hypacusis following his clinical course, but had recovered from all but left hemiparesis following medical treatments including steroid therapy. The histologic finding by a renal biopsy revealed focal glomerulosclerosis. In this case, we considered that when he was in a hypercoagulable state and had a second attack of nephrotic syndrome because of inflammation and dehydration due to diarrhea and appetite loss, his hypercoagulable state grew worse, and he then developed a cerebral infarction. When one see a patient with nephrotic syndrome, one should be attentive to the possibility of a complication of cerebral infarction.
Assuntos
Infarto Cerebral/etiologia , Síndrome Nefrótica/complicações , Adulto , Encéfalo/patologia , Glomerulosclerose Segmentar e Focal/complicações , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
We reported the serial magnetic resonance imaging (MRI) findings of two patients with central nervous system (CNS) cryptococcal infection without AIDS. The diagnosis of CNS cryptococcosis was made by visualizing the fungi in the CSF with the India ink test, detecting cryptococcal antigens, and culturing the fungus. Both patients had dilated perivascular Virchow-Robin (V-R) spaces, which were defined as small rounded lesions greater less than 3mm diameter that were hyperintense on T2-weighted images. They were present in the basal ganglia, brainstem and cerebral white matter. Case 1 had bilateral parietal arachnoid cyst which was thought to represent a focal collection of organisms and mucoid material within subarachnoid space. Abnormal optochiasmatic arachnoid enhancement detected in case 2, who had complete loss of vision. With disease progression perivascular V-R increased in size, resulting in the developing cryptococomas which were defined as rounded lesions greater than 3mm diameter, and were hyperintense on T2-weighted images in the basal ganglia, cerebellum and cerebral white matter. In follow-up MRI of those patients, radiological progression was seen despite appropriate treatment and falling CSF cryptococcal antigens. In conclusion, this spectrum of MRI appearances in CNS cryptococcosis reflects the pathological mechanism of invasion by the fungus, and may be relatively specific for cryptococcosis.
Assuntos
Encéfalo/patologia , Criptococose/diagnóstico , Imageamento por Ressonância Magnética , Meningoencefalite/diagnóstico , Idoso , Cryptococcus/isolamento & purificação , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Arteriosclerose/epidemiologia , Dieta , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , População SuburbanaRESUMO
1. The present study was carried out to investigate the effect of bilateral adrenalectomy on fevers induced in rats by systemic injection of interleukin-1 beta (IL-1 beta) or by central injection of prostaglandin E2 (PGE2). 2. Intraperitoneal (I.P.) injections of two doses of IL-1 beta (0.5 and 1.0 microgram kg-1) induced biphasic fevers in normal control rats in a dose-dependent manner. Adrenalectomized (ADX) rats showed higher fevers than sham-ADX rats after I.P. injection of small doses of IL-1 beta (0.5 micrograms kg-1). This fever enhancement was inhibited by acute or chronic glucocorticoid, dexamethasone (DEX), treatment. In contrast, there was no significant difference between fevers induced in ADX and sham-ADX rats by I.P. injection of large doses of IL-1 beta (1.0 g kg-1). 3. Dose-dependent fevers were observed in normal control rats after injections of several doses of PGE2 (5, 25 and 100 ng) into the preoptic hypothalamic area (POA). The injection of a large dose of PGE2 (100 ng) into the POA led to a lower fever in ADX rats, compared with that in sham-ADX rats. This fever in ADX rats was increased by acute or chronic treatment with DEX. On the other hand, adrenalectomy had no effect on fevers induced by the injections of small doses of PGE2 (5 and 25 ng) 4. The injections of PGE2 (100 ng) into the POA induced increases in oxygen consumptions in ADX rats that were significantly smaller than those in sham-ADX rats, suggesting that the lower PGE2 fever was, at least in part, due to attenuated thermogenesis in ADX rats. 5. There was no significant difference in plasma osmolality between the ADX and the sham-ADX rats. The ADX rats were given 0.9% salt water instead of tap water. 6. These results suggest that endogenous glucocorticoid is one of the important modulators of the IL-1-induced and the PGE2-induced fevers in rats.
Assuntos
Adrenalectomia , Dinoprostona , Febre/induzido quimicamente , Interleucina-1 , Animais , Temperatura Corporal , Dexametasona/uso terapêutico , Dinoprostona/administração & dosagem , Relação Dose-Resposta a Droga , Febre/tratamento farmacológico , Febre/fisiopatologia , Injeções , Injeções Intraperitoneais , Interleucina-1/administração & dosagem , Masculino , Consumo de Oxigênio , Área Pré-Óptica/fisiologia , Ratos , Ratos WistarRESUMO
Interleukin-1 beta (IL-1 beta) production in the brain and the spleen was investigated in rabbits which show febrile tolerance to bacterial endotoxin, lipopolysaccharide (LPS). Febrile tolerance to LPS was induced by daily intravenous (i.v.) injections of LPS (4 micrograms/kg, i.v.) for 5 days. In the LPS-tolerant rabbits, the second phase of the biphasic fever induced by i.v. injection of LPS (4 micrograms/kg) disappeared, although the first phase remained intact. In situ hybridization and immunohistochemical studies revealed that IL-1 beta production was observed in the circumventricular organs, such as the organum vasculosum laminae terminalis (OVLT), subfornical organ (SFO) and area posterema (AP), 1 h after the first exposure to i.v. injection of LPS (4 micrograms/kg) (acute rabbits). In contrast, IL-1 beta production in these circumventricular organs disappeared in the LPS-tolerant rabbits. IL-1 beta production was observed in the spleens of the acute and the LPS-tolerant rabbits after i.v. injections of LPS. The cells which produced IL-1 beta in the spleen following LPS injections were confirmed to be monocytes/macrophages and polymorphonuclear leukocytes by immunohistochemistry in both the acute and the LPS-tolerant rabbits. The LPS-injected acute rabbits showed a significant increase in the number of IL-1 beta-immunoreactive monocytes/macrophages, compared with that in the saline-injected acute rabbits. However, there was no significant difference in immunoreactive cell numbers between the saline-injected acute and LPS-injected tolerant rabbits, or between the LPS-injected acute and the LPS-injected tolerant rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Ventrículos Cerebrais/metabolismo , Interleucina-1/biossíntese , Lipopolissacarídeos/farmacologia , Animais , Tolerância a Medicamentos , Imuno-Histoquímica , Hibridização In Situ , Masculino , Coelhos , Baço/metabolismoRESUMO
Interleukin-1 beta (IL-1 beta) production in the brain and the spleen was investigated in rabbits made febrile by intravenous (I.V.) injection of endotoxin, or human recombinant IL-1 beta (hIL-1 beta). The endotoxin used in the present study was the lipopolysaccharide (LPS) of Salmonella typhosa endotoxin. Monophasic fever was induced by I.V. injection of a low dose of LPS (0.02 micrograms kg-1) and biphasic fever by I.V. injection of a large dose of LPS (4 micrograms kg-1), a sublethal dose of LPS (40 micrograms kg-1) or hIL-1 beta (2 micrograms kg-1). In situ hybridization and immunohistochemical studies revealed that, although no IL-1 beta production was observed in the brain at 1 and 3 h after injection of a low dose of LPS (0.02 micrograms kg-1) or of hIL-1 beta (2 micrograms kg-1), IL-1 beta production was demonstrated in organum vasculosum laminae terminalis (OVLT) and some cells around the blood vessels in the parenchyma 1 h after 4 micrograms kg-1 LPS. IL-1 beta production was detected throughout the brain after 40 micrograms kg-1 LPS. Pretreatment with indomethacin, an inhibitor of prostaglandin synthesis, did not affect IL-1 beta production in the brain induced by 4 micrograms kg-1 LPS. The cell type which produces IL-1 beta in the OVLT following LPS injection was confirmed to be a macrophage by electron microscopy. The cells producing IL-1 beta in the parenchyma were determined to be microglial cells. In the spleen, each dose of LPS induced a significant increase in IL-1 beta production in polymorphonuclear cells and macrophages in the red pulp 1 h after injection. However, 2 micrograms kg-1 hIL-1 beta did not induce IL-1 beta production in the spleen. The present results show clearly that systemic administration of LPS induces IL-1 beta production in the OVLT which may be responsible for induction of the second phase of biphasic fever. The production of IL-1 beta in the OVLT was not attributable to the action of peripherally synthesized IL-1 beta or prostaglandins.
Assuntos
Toxinas Bacterianas , Química Encefálica/efeitos dos fármacos , Endotoxinas , Febre/metabolismo , Interleucina-1/biossíntese , Salmonella typhi/metabolismo , Animais , Ventrículos Cerebrais/fisiologia , Febre/induzido quimicamente , Imuno-Histoquímica , Hibridização In Situ , Indometacina/farmacologia , Macrófagos/metabolismo , Masculino , Microscopia Eletrônica , Plasmídeos , Sondas RNA , Coelhos , Proteínas Recombinantes/metabolismo , Mapeamento por RestriçãoRESUMO
1. We investigated whether afferent nerves are involved in the development of adrenocorticotrophic hormone (ACTH) responses induced either by systemic administration of interleukin-1 beta (IL-1 beta) and prostaglandin E2, or by psychological stress. The capsaicin desensitization method was used to impair afferent C fibres and we compared the ACTH responses between capsaicin desensitized and vehicle pretreated control rats. 2. The present results showed that the capsaicin desensitized rats had significantly smaller increases in plasma ACTH than the control rats in response to intravenous injection of IL-1 beta or prostaglandin E2. 3. There were no significant differences between the capsaicin desensitized and control rats in the ACTH responses induced by cage switch stress. 4. The capsaicin desensitized rats responded to intravenous injection of corticotrophin releasing factor (CRF) with a greater increase in the plasma level of ACTH than the control rats, indicating that capsaicin pretreatment resulted in augmentation of pituitary gland sensitivity to CRF. 5. These results suggest that afferent neurons play an important role in the ACTH responses induced by systemic injection of IL-1 beta or prostaglandin E2.
Assuntos
Hormônio Adrenocorticotrópico/sangue , Capsaicina/farmacologia , Interleucina-1/farmacologia , Prostaglandinas E/farmacologia , Animais , Temperatura Corporal/efeitos dos fármacos , Hormônio Liberador da Corticotropina/farmacologia , Injeções Intravenosas , Interleucina-1/administração & dosagem , Masculino , Fibras Nervosas/efeitos dos fármacos , Fibras Nervosas/fisiologia , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/fisiologia , Prostaglandinas E/administração & dosagem , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Estresse Psicológico/sangueRESUMO
We investigated the role of central corticotropin-releasing factor (CRF) in the development of cardiovascular and thermal responses induced by stress or by interleukin-1 beta (IL-1 beta) in free-moving rats. Intracerebroventricular (icv) injection of alpha-helical CRF9-41 (10 micrograms), a CRF receptor antagonist, significantly attenuated hypertension, tachycardia, and a rise in body temperature induced by cage-switch stress, a mild stress. However, icv injection of alpha-helical CRF9-41 (10 micrograms) had no effect on hypertension, tachycardia, or fever induced by intraperitoneal (ip) injection of IL-1 beta (2 micrograms/kg) or icv prostaglandin E2 (PGE2, 100 ng). In contrast, icv injection of alpha-helical CRF9-41 (10 micrograms) significantly attenuated hypertension, tachycardia, or fever induced by icv injection of IL-1 beta (20 ng). The present results suggest that central CRF has an important role in the development of the cage-switch stress-induced responses, but it does not seem to contribute to the hypertension, tachycardia, and fever induced by ip IL-1 beta or by central PGE2. However, it is possible that when IL-1 beta directly acts on the central nervous system, some of its actions are mediated by central CRF.
Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Sistema Cardiovascular/efeitos dos fármacos , Sistema Cardiovascular/fisiopatologia , Hormônio Liberador da Corticotropina/farmacologia , Interleucina-1/farmacologia , Estresse Fisiológico/fisiopatologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Hormônio Liberador da Corticotropina/antagonistas & inibidores , Frequência Cardíaca/efeitos dos fármacos , Injeções Intraventriculares , Masculino , Ratos , Ratos Wistar , Cloreto de Sódio/farmacologiaRESUMO
The present study was carried out to determine whether interleukin-1 (IL-1) production occurs in the rabbit organum vasculosum laminae terminalis (OVLT) during fever induced by endotoxin. The intravenous (i.v.) injection of endotoxin (4 micrograms/kg) caused significant fever in rabbits. Through the use of in situ hybridization and immunohistochemical techniques, the synthesis of IL-1 was observed in the OVLT during the fever. The present results support the hypothesis that IL-1 is produced in the brain during fever.
Assuntos
Ventrículos Cerebrais/metabolismo , Febre/metabolismo , Interleucina-1/biossíntese , Animais , Endotoxinas , Técnicas Imunoenzimáticas , Hibridização In Situ , Lipopolissacarídeos , Masculino , Coelhos , Salmonella typhiRESUMO
We investigated the effects of intraperitoneal injection of alpha- and beta-adrenergic antagonists on psychological stress-induced responses in free-moving rats. Psychological stress was induced by immersion in 2-cm-deep water. The intraperitoneal injection of the alpha-adrenergic blocker, phentolamine (10 mg/kg), attenuated the stress-induced rise in body temperature and hypertension but enhanced tachycardia. In contrast, intraperitoneal injection of the beta-adrenergic blocker, propranolol (1 mg/kg), suppressed tachycardia but had no effect on rise in body temperature and hypertension during stress. The intraperitoneal injection of both blockers had no effect on the increase in metabolic rate (O2 consumption) induced by stress. The intravenous injection of propranolol (1 mg/kg) suppressed the stress-induced rise in body temperature. We then examined the effect of intracerebroventricular injection of propranolol on the stress-induced rise in body temperature and found that intracerebroventricular injection of propranolol (50 micrograms) suppressed the stress-induced rise in body temperature. These results support the following hypotheses: 1) Systemic injection of phentolamine suppresses the psychological stress-induced rise in body temperature by facilitating heat-loss; 2) Peripheral beta-adrenergic stimulation probably does not contribute to psychological stress-induced rises in body temperature; and 3) central beta-adrenergic receptors are important in stress-induced increases in body temperature.
Assuntos
Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Temperatura Corporal/efeitos dos fármacos , Estresse Psicológico/fisiopatologia , Animais , Imersão , Injeções Intraperitoneais , Injeções Intravenosas , Injeções Intraventriculares , Masculino , Fentolamina/administração & dosagem , Fentolamina/farmacologia , Propranolol/administração & dosagem , Propranolol/farmacologia , Ratos , Ratos Wistar , Estresse Psicológico/etiologiaRESUMO
1. We investigated the central role of corticotrophin-releasing factor (CRF-41) in psychological stress-induced responses, including cardiovascular, thermoregulatory and locomotive activity in free-moving rats. 2. Psychological stress was induced by cage-switch stress. After rats were placed in the novel environment, blood pressure, heart rate, body temperature and locomotive activity significantly increased. The intracerebroventricular (I.C.V.) injection of alpha-helical CRF(9-41), a CRF-41 receptor antagonist, significantly attenuated the stress-induced hypertension, tachycardia, hyperthermia and increase in locomotive activity. However, in unstressed rats, the I.C.V. injection of alpha-helical CRF(9-41) had no effect on physiological parameters measured in this study. 3. In unstressed rats, the I.C.V. injection of CRF-41 (1 microgram and 10 micrograms) increased blood pressure, heart rate, body temperature and locomotive activity in a dose-dependent manner. The changes in these responses were quite similar to those observed during cage-switch stress. 4. The results suggest that central CRF-41 plays an important role in psychological stress-induced hypertension, hyperthermia, tachycardia and increase in locomotive activity. However, it is likely that central CRF-41 does not contribute to normal cardiovascular and body temperature regulation when rats are free from stress.
Assuntos
Regulação da Temperatura Corporal , Sistema Cardiovascular/fisiopatologia , Hormônio Liberador da Corticotropina/fisiologia , Locomoção , Estresse Psicológico/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Regulação da Temperatura Corporal/efeitos dos fármacos , Hormônio Liberador da Corticotropina/antagonistas & inibidores , Hormônio Liberador da Corticotropina/farmacologia , Relação Dose-Resposta a Droga , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Injeções Intraventriculares , Locomoção/efeitos dos fármacos , Masculino , Fragmentos de Peptídeos/farmacologia , Ratos , Ratos WistarRESUMO
The effect of tumor necrosis factor-alpha (TNF-alpha) on the febrile response to interleukin-1 beta (IL-1 beta) was investigated in rats. While both of these substances are capable of causing fever when injected into rats, an earlier study showed that the injection of antiserum against TNF-alpha enhanced endotoxin [lipopolysaccharide (LPS)] fever, suggesting that physiological levels of circulating TNF may act to limit the magnitude of fever. In the present study, the intraperitoneal injection of 1 microgram/kg of TNF-alpha significantly attenuated the fever due to the intraperitoneal injection of 10 micrograms/kg of IL-1 beta. Higher doses of TNF-alpha (10 and 50 micrograms/kg injected ip) slightly lowered the febrile response to this dose of IL-1 beta, but these changes were not significant. None of these doses of TNF-alpha alone significantly altered body temperature. The injection of 1 microgram/kg of TNF-alpha also significantly lowered the febrile response to the intraperitoneal injection of 10 micrograms/kg of LPS. The febrile responses to the preoptic area (POA) or intraperitoneal injection of IL-1 beta were not changed when a nonpyrogenic dose of TNF-alpha was simultaneously injected into the POA. Further studies are needed, however, before we can conclude that TNF does not act in the central nervous system to control the febrile response. These data support the hypothesis that nonpyrogenic levels of TNF act in the systemic circulation to suppress the development of fever.
Assuntos
Febre/induzido quimicamente , Interleucina-1 , Lipopolissacarídeos , Fator de Necrose Tumoral alfa/farmacologia , Animais , Temperatura Corporal/efeitos dos fármacos , Febre/fisiopatologia , Injeções , Injeções Intraperitoneais , Masculino , Área Pré-Óptica/fisiologia , Ratos , Ratos WistarRESUMO
1. We investigated the effect of intraperitoneal (I.P.) injections of the immune cytokines, interleukin-1 beta (IL-1 beta) and tumour necrosis factor (TNF) on cardiovascular responses in free-moving rats, using a biotelemetry system. 2. The I.P. injection of a small dose of IL-1 beta (1 microgram/kg) induced a monophasic increase in the heart rate, and that of a large dose (10 micrograms/kg) induced biphasic increases in the blood pressure and heart rate. However, the I.P. injection of any of several doses of TNF (1, 10 and 50 micrograms/kg) had no effect on cardiovascular responses in rats. 3. Pre-treatment with I.P. injection of indomethacin (10 mg/kg), an inhibitor of cyclo-oxygenase, significantly suppressed the cardiovascular responses and the increase in the plasma noradrenaline (NA) concentration induced by I.P. injection of IL-1 beta. 4. Microinjection of IL-1 beta (1 and 10 ng) into the preoptic and anterior hypothalamic (PO-AH) region induced dose-dependent increases in the blood pressure and heart rate in rats. These responses were also suppressed by pretreatment with I.P. indomethacin (10 mg/kg). In addition, microinjection of prostaglandin E2 (20 and 100 ng) into the PO-AH region increased blood pressure and heart rate, but that of prostaglandin D2 (100 ng) had no effect. 5. The present results suggest that IL-1 beta stimulates the release of prostaglandins, presumably E series, near regions of the hypothalamus, which act on the hypothalamus to induce activation of the sympathetic nervous system. Subsequently, the blood pressure, heart rate and the plasma level of NA increase.